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Danny’s DNA Discoveries – Tremellomycetes (Parasitic Jellies) of the PNW
by Danny Miller

Click here for my Pictorial Key to the Tremellomycetes


Jelly fungi are not brittle at all but gelatinous. It's very hard to tear one and they can't easily be crushed or broken. They are some of the most basal groups of  "basidio" fungi, implying this could have been one of the first types of mushroom fruiting bodies to evolve (some others are rusts and smuts). The two most basal classes of "basidios", the Tremellomycetes and Dacrymycetes are mostly jellies. The class Agaricomyces contains the "higher" order basidios. Many if not most species of the most basal orders of that class are jellies (the Auriculariales, Sebacinales and Tremellodendropsidales). Even some Cantharellales, another somewhat basal order, are jelly crusts.

Tremellomycetes usually take the form of jelly drops on wood or on a host, or of witch's butter (folded jellies on wood). They are also ecologically distinct for being parasitic. When they grow on wood, they often are parasitizing a saprophytic fungus in the wood that may or may not be visible at the time, and if not, they are easily confused with other jelly fungi in the Dacrymycetes and Auriculariales, which are usually saprophytic and not parasitic. When they grow directly on other mushrooms or lichen it is easier to recognize a jelly mushroom as parasitic and therefore in this class. They usually parasitize crust fungi in the Russulales (Peniophora, Stereum, Acanthophysium or Aleurodiscus), Sordariomycete crusts ('asco' flask fungi that are often black, carbonous and pimpled) or lichens, but one parasitizes a gilled mushroom. I only cover species large enough to see with the naked eye on this page. Asexual reproduction is common in this class too. Those spores look very different than the sexual spores and the fruiting body may even look different in different stages.

All jellies are unusual by being one of a few groups of mushrooms called "heterobasidiomycetes", instead of "homobasidiomycetes" (although since "basidiomycete" changed to "basidiomycota" when "basidios" moved from a class to a phylum, I suppose we should be calling them "heterobasidiomycota"). Basidia usually all look the same, and the majority with that similar look are called "homobasidiomycetes" (homo=same). The few that are different are called "heterobasidiomycetes" (hetero=different). They can differ in two ways, one, by looking like a tuning fork (Dacrymycetes) or two, by being septate (often longitudinally so) but more importantly, with long sterigmata which are the stems that the spores grow on (all other jellies). They are jellies because their basidia are protected in a gel, and they need long sterigmata for them to reach out of the gel and grow the spores. Telling the Tremellomycetes apart from some other jellies (except the tuning fork Dacrymycetes), especially Exidia, is going to be difficult. The best way is to detect the parasitism or just learn the species.

The entire class is well covered in this excellent paper by Liu et. al: Towards an integrated phylogenetic classification of the Tremellomycetes. That paper has an LSU tree constrained by a multi-gene tree, and I am basing my genus placements on that tree. You will note that in my ITS-only tree, The genera 'Tremella1', 'Tremella2' and Pseudotremella do not hold together, but occur in more than one place in my tree. Perhaps this is expected as the tree is attempting to document an entire class. Can you imagine trying to put all non-jelly basidios in a single tree? They represent one class. There are probably not enough genera in the tree to even be able to hold the genera together, never mind the families. I generally agree with the Liu paper, however, there may be one mistake as our local species PNW01 clades with almost 100% support next to both a Liu 'Tremella2' species and a Liu Pseudotremella species. Those genera are in different families, so one of the sequences must be mixed up. Which genus is our species in? It seems to be in the Pseudotremella part of the tree with high support.

abundant common uncommon rare - colour codes match my Pictorial Key and are my opinions and probably reflect my bias of living in W WA. Rare species may be locally common in certain places at certain times.

Tremella s.l.

Genetics has split this genus up so it is difficult to know the genus of one of the jellies on this page by sight.

Tremella mesenterica EU - witch's butter. This blob of jelly is somewhat irregular with some to many folds and is usually translucent yellow. It parasitizes species of Peniophora on hardwoods. You won't always get lucky to see them both fruit at the same time, but here you can see both the Peniophora host and the Tremella parasite on the same stick. This sequence from WA matches many EU sequences.

Tremella mesenterella BC - very similar, perhaps a little smaller, with rounder spores, usually on dogwood or willow. We do not have DNA of this local species yet.

Tremella globispora UK - colourless to whitish wrinkled blobs (4-5 mm) on the underside on twigs parasitic on Sordariomycetes (flask fungi). Being white, this species resembles 'Tremella1' PNW02, below, but we have the type sequence of T. globispora and it is indeed a true Tremella and not that species. We need local collections to prove T. globispora does occur here.

Naematelia aurantia EU - usually larger than T. mesenterica with many folds, opaque yellow to orange-yellow. It parasitizes species of Stereum, usually on hardwoods. Once again, you can see both the Stereum host and the Naematelia parasite on the same log here. The similar 'Dacrymyces' chrysospermus grows on conifers with a white point of attachment sometimes visible where it attaches to the wood. Our one somewhat short WA sequence is 3 bp different in ITS1 then sequences found in the EU, ENA and Russia, and they all probably represent this species.

Naematelia encephala EU - pinkish to yellowish wrinkled brain-like blobs, with a hard, white centre. It parasitizes Stereum sanguinolentum, meaning it is found on conifers, unlike most 'Tremella' which usually parasitize hardwood hosts. A couple of BC sequences match one EU sequence, so I think we have this species, but we don't have any sequenced local photos.

Tremella mesenterica parasite and Peniophora host © Yi-Min Wang,     Naematelia aurantia parasite and Stereum host © Yi-Min Wang,     unsequenced N. encephala © Buck McAdoo


Phaeotremella frondosa EU - a very folded caramel brown species, parasitic on Stereum that inhabit hardwoods. One WA sequence matches the type sequence well.

Phaeotremella foliacea EU - similar, parasitic on Stereum sanguinolentum that inhabit conifers. One OR and one AZ sequence match the type sequence well.

Phaeotremella cf mycetophiloides - perhaps described from Japan. Quite different than other Phaeotremella and not easy to recognize to genus. They are minute (~1 mm) clear to pale pink or yellow jellies parasitic on Aleurodiscus crusts on conifers. Aleurodiscus is also in the Russulales. We have a sequence from the EU purporting to be this, but no clear idea of the type area. This unsequenced photographed collection shows Aleurodiscus on the same stick. We need local sequences.

Phaeotremella frondosa © Sharon Squazzo,     P. foliacea © Jonathan Frank,     unsequenced P. cf mycetophiloides © Danny Miller


Tremella1 PNW02 - This white species has good support for being inside the unnamed genus Liu calls 'Tremella1'. Sequenced once from OR.

Pseudotremella PNW01 - with black pustules growing under the bark and pushing it away. It resembles Pseudotremella moriformis UK, also reported from the PNW. Sequenced once from OR. It should be noted that PNW01 clades with almost 100% support next to both a Liu 'Tremella2' species in the Naemateliaceae family and a Liu Pseudotremella species in the Bulleraceae family. I believe there is some mistake in the data. My ITS tree has strong support for PNW01 being in the Pseudotremella part of the tree, so that is where I am placing this species.

Pseudotremella moriformis UK - reddish brown to black tough gelatinous jellies on hardwoods around 1 cm in size, with a hard black core that may be the Sordariomycete host. Liu provides sequences of this but we have no PNW sequences yet to compare.

'Tremella' cf subanomala NC - up to 4 cm cushion shaped colourless then cinnamon then blackish jellies on hardwoods. I don't know the host. As it is described as similar to or the same as Tremella indecorata EU, and that species is either in Pseudotremella or 'Tremella2', depending on which sequence you believe. Liu places the type sequence of T. indecorata in 'Tremella2', but there is a mistake in the data (see PNW01 above) that calls this into question. A sequence of a collection by Bandoni that is probably from BC, purporting to be Tremella subanomala, is inside Pseudotremella. This implies that T. subanomala does occur in the PNW as reported and that it belongs in Pseudotremella. We need east coast type or other reliable sequences to find out for sure.

'Tremella1' PNW02 © Leah Bendlin,     Pseudotremella PNW01 © Leah Bendlin (2 images)


Carcinomyces effibulatus EU - a microscopically thin film covering galls on Gymnopus dryophilus. It would be undetectable to the naked eye if it were not for the galls it causes to grow on the mushroom. It would not be recognizable as being related to these jelly fungi except the galls it creates do happen to be somewhat gelatinous. ENA sequences match EU sequences, but we have no local sequences yet to confirm that is our species too.

unsequenced Carcinomyces effibulatus © Buck McAdoo


Other, tiny species reported from the PNW, with the true genus given:

Parasitic on 'asco' flask fungi on wood

  • Tremella1 exigua EU - minute (~1 mm) greenish white discs parasitic on Sordariomycetes (flask fungi). We have a sequence purporting to be this in Liu genus 'Tremella1'.

Parasitic on 'basidio' crusts on wood

  • 'Tremella' subencephala YT - minute (~1 mm) jellies but sometimes growing together to form larger masses, growing on Acanthophysium crusts on wood. These crusts, like Peniophora and Stereum are all in the Russulales. No DNA yet, so its true genus is unknown.
  • Tremella versicolor UK - small (a few mm) orangish jellies on Peniophora crusts on hardwood shrub stems. We have an EU sequence purporting to be this and it is a true Tremella.

Parasitic on lichens

  • 'Tremella' papuana Papua New Guinea - minute (~1 mm) white when young to black when old jellies also parasitic on Hypogymnia lichen. No DNA yet, so its true genus is unknown.
  • Tremella2 nephromatis BC -minute (~1 mm) brownish jellies parastic on Nephroma lichen. As a local species, this definitely occurs here, whatever it is. We have a sequence from somewhere (the EU?) purporting to be this in Liu genus 'Tremella2'.
  • Tremella2 cladoniae EU - minute (~1 mm) pinkish-brown galls and then jellies parasitic on Cladonia lichen, the same host as Heterocephalacria bachmanii. We have a sequence purporting to be this in Liu genus 'Tremella2'.
  • Tremella3 cetrariicola UK - a minute (~1 mm), reddish-brown to black jellies parasitic on Cetraria and Tuckermannopsis lichen. We have a sequence purporting to be this in Liu genus 'Tremella3'.
  • Tremella3 hypogymniae EU - minute (~1 mm) pinkish brown galls and then yellow- pink- or orange-brown jellies parasitic on Hypogymnia lichen. We have a sequence purporting to be this in Liu genus 'Tremella3'.
  • Tremella3 lichenicola EU - minute (~1 mm) brownish jellies parasitic on Mycoblastus lichen. We have a sequence purporting to be this in Liu genus 'Tremella3'.
  • Tremella3 lethariae BC -minute (~1 mm) brownish galls and then jellies parasitic on Letharia lichen. As a local species, this definitely occurs here, whatever it is. We have a sequence from the US purporting to be this. We have a sequence purporting to be this in Liu genus 'Tremella3'.
  • Tremella3 huuskonenii BC - minute (~1 mm) black jellies parasitic on the lichen Phacopsis huuskonenii, which itself is parasitizing Bryoria lichen and creating galls on them. We have the type sequence (it is in Liu genus 'Tremella3'), but no photos.
  • Heterocephalacria bachmannii EU - small (a few mm) brownish jellies also parasitic on Cladonia (and Cladina) lichen, the same host as 'Tremella2' cladoniae. I do have many EU sequences of this one, but no local sequences to compare to.
  • Heterocephalacria physciacearum EU - minute (~1 mm) brownish jellies parasitic on Heterodermia, Physcia, and Physconia lichen. I do have one possible EU sequence of this species, but no local sequences to compare to.


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